This proposal seeks to test the effectiveness and cost-effectiveness of two mailed, population-based interventions designed to increase mammography use among medically underserved women age 40 to 84. Both interventions are designed to promote use of mammography services available through two national programs: the Centers for Disease Control and Prevention's (CDC) National Breast and Cervical Cancer Early Detection Program (NBCCEDP) and Medicare. One intervention uses personally addressed mailings to encourage women to get a mammogram, while the other intervention uses a combination of personally addressed mailings, a toll-free number, and direct appointment scheduling to encourage women to get a mammogram. Because of age-related differences in both insurance coverage for and barriers to mammography use, as well as in the availability of data to adequately measure mammography use, this proposal is divided into two studies. One study targets younger women age 40 to 64 who are eligible for mammography services through the NBCCEDP in Minnesota, while the other study targets older women age 65 to 84 who are eligible for mammography services through either Minnesota's NBCCEDP or Medicare. The study samples will be randomly drawn from the Minnesota driver's license database for the study of younger women, and from Medicare's enrollment file for the study of older women. A total of 15,201 women age 40-64 and 7,134 women age 65-84 will be randomly assigned to one of two intervention groups or a control group. A randomized post-test only control group design will be used to test for differences in the proportion of women getting a mammogram one year after receiving the mailings based on claims data from the state program and/or Medicare. If this study can demonstrate the effectiveness of a low-cost strategy for increasing mammography use among underserved populations, it can significantly contribute to reaching national public health goals for improving the health of all women. The potential for widespread incorporation of the proposed interventions are substantial because they are designed to be readily implemented by state and local health departments.